Donepezil, a Hexahy dropyridine oxide, is the second generation of specific reversible central acetylcholinesterase (AChE) inhibitor with little effect on peripheral ache. This product can slow down the decomposition of acetylcholine (ACh) in synaptic space by inhibiting the activity of ache, so as to increase the content of ACh and improve the cognitive function of patients with Alzheimer's disease (AD). The inhibition of acetylcholinesterase activity was 570 times stronger than that of butyrylcholinesterase, and it had high selectivity. Oral administration of 10 mg / kg can inhibit cholinesterase in brain in a dose-dependent manner.